Confluence – Creating an Auto-Updated Copy of Another Page

I have two separate Confluence spaces which shares some identical pages that I need to update from time to time and I want these pages to have exactly the same content in both spaces.

I see four options:

1. Maintain (update) two separate copies, in each space, totally manually.
2. Use fake pages like Go to: [link] in one space to link to another one.
3. Force (if possible) Confluence to add link to second space in first space's sidebar.
4. Use a macro (or any other solution) that will be changed into exact copy of given page in another space and will be then somehow auto-updated.

I have tested first and second solutions and I can keep using them, if I don't find any alternatives, but they are — of course — not very professional ways of solving this problem.

Unfortunately, I don't have corresponding privileges to make use of third option.

For fourth solution I need to find such macro or craft one myself and this is more like question for Stack Overflow than for this page.

But maybe there is any non-macro, "clickable" way of achieving this — through Confluence base functionality or some "magical" configuration switch? (I don't have required privileges, but I can always try to reason my Confluence's admin to click some things for me, if such solution exists)?